Signaling system



K. s. JOHNSON. SIGNALING SYSTEM.

APPLICATION FILED DEC-29, l9l6- 1,435,240. Patentedllov. 14,1922.

M wn for: Kenn WV? 5. Johnson:

Patented Nov. 14, 1922.

omrso STATES PATENT OFFICE.

KENNETH S. JOHNSON, OF JERSEY CITY, NEW JERSEY, ASSIGNOR TO WESTERN ELEC- TRIO COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

SIGNALING svsrnivr.

Application filed. December 29, 1.916. Serial No. 139,632.

Systems, of which the following is a full,-

clear, concise, and exact description.

This invention relates to means and ap-' paratus for signaling.

M ore particularly, ,it relates to means for establishing communication between an an chored balloon and the ground. 1

Balloons, such as are used for observation purposes, are generally anchored to earth by some suitablemeans, such as a single metallic cable, which controls the height of the balloon above the ground. It is very often desirable to have some means for intercomniunication between said balloon and the ground. The object of this invention is to furnish a simple and eflicient means for carrying on such communication without introducing any additional conductors between the balloon and the earth, and without adding appreciably to the weight supported by the balloon.

For the accomplishment of this purpose this invention employs the conducting qualities of the single cable connecting the balloon to earth as one side of a signaling circuit for the the circuit by means of the capacity between the balloon and the ground. A source of low frequency signals and means for detecting them is provided at both the earth and the balloon end of the signaling circuit, whereby the intercommunication between the balloon and the earth may be established.

For the better understanding of this invention reference is made to the accompanying drawing, which represents an embodimeat of this invention as adapted for signaling by means of voice currents In the drawing, the balloon 1 is shown anchored to the ground by means of the conducting cable 2. This cable is connected to the conductive network or surfaceof the balloon at the point 3. The capacity between the conductive surface of the balloon and the ground is represented by the condenser 4. The combination of this condenser and the grounded cable constitutes the signaling circuit. In the combined transtransmission of signals, and completes mitting and receiving system at the balloon, 5 is a telephone transmitter for which a source of current 6 is provided; 7 is a telephone receiver; 8 is an auxiliary impedance whose function will be described later. At the earth end is a transmitter 10 supplied with current from the source 11; 12 is a telephone receiver; and 13 an auxiliary impedance similar to impedance 8.

If, now, it is (:lesired to signal from the balloon to the earth, low frequency oscillations from the transmitter 5 are impressed on the signaling circuit by means of transformer 14-. At the earth end, by means of transformer 15, they actuate the receiver 12. Similarly, if it is desired to signal from the earth to the balloon, the low frequency oscillations from the source 10 are impressed on the telephone circuit by means of the transformer 15. At the balloon end transformer 1 1 impresses the signals upon the receiver 7.

In order to increase the amount of current flowing in the telephone circuit comprising the cable 2 and the condenser 4:, it may be found desirable to increase the capacity of the condenser. In the case where the network 2 1 of the balloon is of insulating material, such as a rope netting, this increase may be accomplished by encircling said balloon by a conductive network of any suitable complexity.

ln general it may be found desirable to provide means in the combined transmitting and receiving systems for preventing oscillations from the transmitter from actuating the receiver associated with it, thereby eliminating the so-called side tone efl'ect. One way for accomplishing this result is to include a transmitter and receiver of equal impedance in series with the transformer winding and to shunt said receiver and onehalf of said transformer winding by means of a non-inductive impedance, whose absolute value is equal to one-half that of the transmitter or that of the receiver. With such an arrangement it has been shown by Campbell in his U. S. Patent No. 1254;,172, issued January 22, 1918, that no oscillations in c-urrentproduced by the transmitter can flow through the receiver associated with it. This arrangement is the one illustrated in the accompanying drawing. 8 is an impedance shunted around the receiver 7 and the part v18 of the transformer 14:, and has an impedance approximately equal to one-half the impedance of the transmitter 5 or receiver 7. This arrangement makes the sidetone in the receiver 7 inappreciable.

In a similar manner receiver 12 and the part 17' of transformer 15 are shunted'b'y means of the impedance 13, thereby preventing oscillations from the transmitter 10 from affecting the receiver 12 to an appreciable degree. d

In order to prevent the windings or the transformer 14 from being subjected to the tension necessary on the cable, they are shunted around an insulating medium shown here as a porcelain insulator 20 to which the anchorlng cable proper is at tached.

The insulation 20 may be located in the basket 23 of the balloon or it may be inserted in the cable some distance below the basket as is shown in the drawing. In the latter case, the lead wires from the transformer to the receiver and transmitter should be of such a length that said apparatus may be conveniently located for the operator in the basket. 7

As it is desirable to have some means for regulating the height of the balloon above the" ground, a Windlass or winch. 25 is provided upon which the cable may be wound or unwound. This Windlass is insulated from the earth by means of insulation 26. The conductive path from the balloon to the earth is continued to the ground by means oii'that part 27 of the cable which ends in the ground connection. 28. This part of the cable is connected to the main portion by means of the adjustable contact 29, which be in contact with the coils on the Windlass, as shown, or the connection may be made to any other point metallically connected to the cable.

It is apparentthat this invention is not limited to the particular type of transmitting-and receiving sets employed in the accompanying drawing, but any of the other types ormodifications thereof known to the artmay be used if desired.

lVhat is claimed .is

1. In a signaling system, an aerial vessel,

mitting and receiving means atv the aerial vessel end being connected in shunt to a portion of said anchoring means and thereby relieved of the tension in said anchoring means.

2. In a signaling system, an aerial vessel, means having high electrical resistance, a conducting strand between said vessel and said means, a conducting strand between said means and earth, a coil having one terminal connected toone of said strands and ansaid terminals, a Windlass for varying the efi'ective length of said cable, a circuit connecting said windlass to ground, and an anti-sidetone substation set at the ground end comprising a repeating coil, the secondary winding of which is included in said last-mentioned circuit.

LAn aerial vessel having an appreciable capacity to ground, anchoring means com prising an electrical insulator and an electrical conductor of variable length between said vessel and ground, two signaling circuits associated with said conductor, one of said signaling circuits being in shunt to said insulator, and a Wll'lCllilSS located between said signaling circuits.

5. A signaling system comprisng an electrical cable having two dead-ended spans, oneend of said cable being grounded, means having an appreciable capacity to ground at the ungrounded end of said cable, an electrical circuit comprising said conductor and said capacity means, and an outgoing circuit connected between said spans.

6. The combination of a conveyance, a cable therefor for positioning said conveyance having two dead-ended spans, means for impressingcurrents upon said cable; electrical apparatus in said conveyance and circuit connections, between said spans and said apparatus.

Tn witnesswhereof, I hereunto subscribe myname this (28th day of December, A. D. 1916.

KENNETH, s. JOHNSON. 

